# 27 28 28 triangle

### Acute isosceles triangle.

Sides: a = 27   b = 28   c = 28

Area: T = 331.1633007445
Perimeter: p = 83
Semiperimeter: s = 41.5

Angle ∠ A = α = 57.65108983208° = 57°39'3″ = 1.00661979924 rad
Angle ∠ B = β = 61.17545508396° = 61°10'28″ = 1.06876973306 rad
Angle ∠ C = γ = 61.17545508396° = 61°10'28″ = 1.06876973306 rad

Height: ha = 24.53105931441
Height: hb = 23.65545005318
Height: hc = 23.65545005318

Median: ma = 24.53105931441
Median: mb = 23.67548812035
Median: mc = 23.67548812035

Inradius: r = 7.98798315047
Circumradius: R = 15.98800457208

Vertex coordinates: A[28; 0] B[0; 0] C[13.01878571429; 23.65545005318]
Centroid: CG[13.67326190476; 7.88548335106]
Coordinates of the circumscribed circle: U[14; 7.70546649011]
Coordinates of the inscribed circle: I[13.5; 7.98798315047]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 122.3499101679° = 122°20'57″ = 1.00661979924 rad
∠ B' = β' = 118.825544916° = 118°49'32″ = 1.06876973306 rad
∠ C' = γ' = 118.825544916° = 118°49'32″ = 1.06876973306 rad

# How did we calculate this triangle?

Now we know the lengths of all three sides of the triangle and the triangle is uniquely determined. Next we calculate another its characteristics - same procedure as calculation of the triangle from the known three sides SSS. ### 1. The triangle circumference is the sum of the lengths of its three sides ### 2. Semiperimeter of the triangle ### 3. The triangle area using Heron's formula ### 4. Calculate the heights of the triangle from its area. ### 5. Calculation of the inner angles of the triangle using a Law of Cosines ### 6. Inradius ### 7. Circumradius ### 8. Calculation of medians #### Look also our friend's collection of math examples and problems:

See more informations about triangles or more information about solving triangles.